PDA

View Full Version : Broken-up Asteroids Found Orbiting White Dwarfs



Fraser
2009-Jan-05, 07:50 PM
Astronomers studying white dwarfs have found the remains of "shredded" asteroids around some of these dead stars. This finding suggests that the same materials that make up Earth and our solar system's other rocky bodies could be common in the universe. If the materials are common, then rocky planets could be, too. "If you [...]

More... (http://www.universetoday.com/2009/01/05/broken-up-asteroids-found-orbiting-white-dwarfs/)

Messier Tidy Upper
2009-Nov-16, 05:30 AM
Did we ever think that "the same materials that make up Earth and our solar system's other rocky bodies" were really going to be that *uncommon*? ;-)

"If you .." what? ;-)

There have I think been a number of such cases of white dwarfs with dusty remnants & of course also the pulsar planets around PSR 1257+12 & PSR B1620-26's "Genesis" or "Methuselah" planet to suggest this.
See : http://www.space.com/scienceastronomy/090420-mm-solar-system.html

Quoting from there :


At least one in every 100 white dwarf stars may be orbited by asteroids and rocky planets, new observations from NASA's Spitzer Space Telescope suggest. ...

... Data from Spitzer suggest that at least 1 to 3 percent of white dwarf stars are contaminated in this way. Scientists think that the out-of-place elements come from a gradual rain of orbiting dust onto the [white dwarf] sun. ... The dust is entirely contained within what is called the Roche limit of the star, or close enough that any object larger than a few kilometers would be ripped apart by gravitational tides. (This is the same phenomenon that produced Saturn's rings.) Because of the location of the dust, scientists think that the dust may originate from rocky bodies such as asteroids (also known as minor planets) that were torn apart in this way. This could mean that as many as 5 million white dwarfs in our own Milky Way are surrounded by orbiting asteroids.

There's also an article on this & related issues in 'Astronomy' magazine July 2009 : "How dying Stars bring new Planets to Life" by Ray Villard, Pages 22 -27.

Still great news though even if it is old news! :-)


PS. Oh wait, the OP was posted Jan. 6th this year - & I'm first to reply? Surprising!

01101001
2009-Nov-16, 06:23 AM
PS. Oh wait, the OP was posted Jan. 6th this year - & I'm first to reply? Surprising!

This subforum is mainly for the purpose of announcing each new article to appear in Universe Today, and discussions thereof. The lead topic articles are posted by an automatic process, with text sample extracted from the story. The quoted matter may appear unusual if you assume a human did it.

Despite the subforum's description stressing "discussion", often topics here don't get any comments. The more discussable news items will often get their own topics, posted by human members, in other parts of BAUT Forum.